Campbell said investigators believe the post refers to the man who killed six and injured 14 in a drive-by shooting and vehicle ramming attack near the University of California Santa Barbara campus in 2014. Rodger later died from an apparent self-inflicted gunshot wound.

Investigators said Rodger was motivated to carry out his attack by a personal grievance related to his immersion in the extremist ideological subculture of men’s rights activists, who believe women don’t actually want gender equality and have been brainwashed by feminist propaganda.

A mile-long scene of carnage

Authorities said Minassian left a trail of destruction nearly a mile long, north of midtown Toronto.

“Based on witness accounts, we have a vehicle that started north on Yonge Street from Finch (Avenue) and drove southbound at some point in times on sidewalks, at some point in times driving southbound in northbound lanes,” Saunders said, adding that it appeared to be a deliberate act.

Ten people were transported to Sunnybrook Health Sciences Centre and two were declared dead at the hospital. Five patients there were in critical condition. Two other patients were taken to St. Michael’s Hospital, but their conditions are unknown.

‘Scene from a war zone’

Diego DeMatos was one of the good Samaritans who tried to save victims.

DeMatos said he was driving north on Yonge when he saw the van driving fast southbound. He said he saw the van hit a man and a woman.

“Blood started gushing out of his head, and she was bleeding really badly, too,” DeMatos told CNN.

At first, he thought the collision was a hit-and-run. But then he noticed four to five victims on the ground as he drove a few meters further.

DeMatos said he stopped to help another victim, who was already being aided by someone.

“I went over to try to perform CPR on him. … He died in our arms,” DeMatos said.

“It was like a scene from a war zone. There was garbage cans everywhere, broken bus shelters and mailboxes on the ground.”

A dramatic arrest

Cell phone video obtained by CNN partner CTV appears to show a tense standoff with a suspect after the incident. Police have not said whether the person in the video was Minassian.

The footage appears to show a man standing in front of a white van with a damaged front bumper. The man is yelling and extending one arm, pointing an object at an officer standing behind a black car.

The officer has his weapon drawn and pointed at the man. The officer slowly steps toward him and yells “Get down, get down!”

Later in the video, the man is seen on the ground and the officer is cuffing his hands behind him; the object can be seen lying on the ground off to the side.

As for whether the suspect had a weapon, “There’s nothing that indicates he has a gun,” Saunders said.

Trudeau offered his condolences to the families of the victims. He thanked first responders, who he said “faced danger without hesitation, and their efforts no doubt saved lives and prevented further injuries.”

“We should all feel safe walking in our cities and communities,” he said. “We are monitoring this situation closely, and will continue working with our law enforcement partners around the country to ensure the safety and security of all Canadians.”